High power microelectronic modules, such as modules containing RF semiconductor die and other circuitry, are often prone to excess heat generation during module operation. In the absence of an adequate thermal solution for dissipating heat from the module, elevated local temperatures or “hot spots” can develop within the microelectronic module and detract from module performance. Existing thermal solutions implemented by manufacturers typically rely upon increasing the metal content within the module substrate in some manner; e.g., by forming bar vias within the body of the module substrate or by installing a prefabricated metal body, such as a Cu coin or slug, within a cavity formed in the module substrate. Such thermal solutions are generally effective at enhancing heat dissipation from microelectronic modules containing heat-generating devices, within limits. Nonetheless, there exists a continued demand within the microelectronic industry for still further enhancements in the heat dissipation capabilities of microelectronic modules.
For simplicity and clarity of illustration, descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the exemplary and non-limiting embodiments of the invention described in the subsequent Detailed Description. It should further be understood that features or elements appearing in the accompanying figures are not necessarily drawn to scale unless otherwise stated. For example, the dimensions of certain elements or regions in the figures may be exaggerated relative to other elements or regions to improve understanding of embodiments of the invention.